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I have a program written recursively which, due to its nature, will fluctuate dramatically and thus, go over Python's limit. The shape of the program is also quite important, so I'd rather not change that.

I've come across increasing the recursion limit like so:

sys.setrecursionlimit(1500)

My question is whether or not it is advisable in my situation to increase the recursion limit like this? I've seen people advise against it for numerous reasons.

LeCodex
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MehmetDirk
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2 Answers2

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sys.setrecursionlimit(1500)

is perfectly fine for increasing recursion depth.(within reason!) You've posted no code, though if there is "wild fluctuations", this is not a stable solution. Python by-and-large should not be used for deep recursion. It seems to me that you have 3 options: 1. De-construct your function and do things iteratively, as opposed to recursion.

If you have your heart truly set on recursion: 2. Use Java recursively 3. Use C++ recursively

DariusFontaine
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    Yes, definitely not a "functional" language. – MrName Aug 24 '17 at 19:03
  • @MrName: If you want functional language extensions for Python, look at [Coconut](http://coconut-lang.org/), it does tail-call optimization allowing for infinite-recursion style. – 9000 Aug 24 '17 at 20:42
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Not a solution, per se, but you might be able to leverage the functools.lru_cache function decorator to memoize your recursive function and prevent it from running to full depth.

Without any insight into what you're doing, it's tough to know if this will be possible. If it's just a simple recursive mathematical function (e.g. Fibonacci numbers), you might have some luck with this approach.

The advantage is that you don't have to make any structural changes to your code--just add @lru_cache(maxsize=None) at the top of your function definition.

Drew Hall
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